Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	May 31, 2012	May 31, 2012 Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executives whose employment was terminated		3
Additional stock-based compensation expenses related to separation and acceleration vesting	$ 1.2	$ 1.8
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)		3
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)		3
Minimum [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)		4
Maximum [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)		5